Mechanical horn.



M. R. HUTGHISON. MECHANICAL HORN.

APPLICATION FILED MAR. 1, 1913. 1 131,636 Patented Mani), 1915.

2 SHEETSSHEET 1.

ATTORNEYS M. R. HUTCHISON.

' MECHANICAL HORN.

APPLICATION FILED MAR. 1, 15:13.

1,131,636. Patented Mar. 9, 1915.

2 SHEETS-SHEET 2.

WITNESSES g 4; @vLmTTOH/VEVS .DfiSTATES PATENT OFFICE.

MILLER. REESE Horomson', 61 WEST ORANGE, NEW JERSEY, ASSIG-NOR T Lov LL-MoGONNELL MANUFACTURING COMPANY, A CORPORATION or DELAWARE.

MECHANICAL HORN.

' Specification of Letters Patent.

Patented Mar. 9, 1915.

Application filed March 1, 1918. Serial No. 751,481.

ments in ,MechanicalI-Iorns, .of which the following is a specification.

In my Patent No. 923,049, issued May 25th, 1909, and in my Patent No.883,643, issued March 31st, 1908,-I have described the various preferredconstructions and operations of a horn wherein the sound is caused byoperation of the rotary cam upon an elastic diaphragm. I have alsoexplained certain desirable features of the cam and of a cooperatingthrust member or anvil on the diaphragm, whereby I sought toja'void Suchlateral tilting of the contact piece and reverse bending of thediaphragm as is disclosed in the Bapst and Falize Patent 384,412,granted June 12th, 1888. In my Patent No. 923,048, issued May 25th,1909, I show and describe, but do not claim, a horn or resonator and adiaphragm, in combination with a rotary memberhaving an eccentric thrustsurface, a thrust member driven by said eccentric'surface, a guide for.confining the motion of said thrust member to a direction perpendicularto the diaphragm, and means for rotating said rotary member sons todisplace said thrust memher at rates corresponding to the frequency ofdesired notes to be produced. Y

My present invention relates to devices of the above type and thepresent application is a division'of my prior application, Serial No.494,688 filed May 7th, 1909, and copending with the applications of,Patents Nos. 923,048 and 923,049 above referred to.

My present invention particularly involves the use of a thrust memberindependent of the diaphragm and preferably free to rotate in respectthereto and about its own axis and held inposition by a guide whichprevents movement of the thrust member except about its own axis ortoward and from the diaphragm. The thrust'of the cam is thus transmittedto the diaphragm /through an intermediate thrust member 7 which is notfixed to the diaphragm, but

which is suitably guided, so as to prevent lateral movement of itselfand to prevent lateral movements of the diaphragm or tilting stresses inthe latter.

- Another feature of my invention consists in so shaping thethrustmember that it is impossible for it to bind or become caught in theguide.

Reference is to be had to the accompanying drawings in which similarreference characters indicate corresponding parts throughout the severalviews.

:Figure 1 is a vertical section showing one embodiment of the inventionas applied to an alarm or signaling device of the general constructionemployed in the commercialKlaxon horn. Fig. 2 is a transverse sectiontaken substantially on the line 22 of Fig. 1; and Figs. 3, 4, 5 and 6are details showing modified forms of thrust members and supportstherefor.

My present invention is applicable to horns or signaling devices varyingwidely in detail from that illustrated as will be apparent from aconsideration of the appended claims. In this specific form thediaphragm 1 is clamped at the edges between two sections of an inclosingcase, the rear section 2 of which is-formed with rear wallsapproximately parallel with the diaphragm, except where it is enlarged,as at 3 and 4, to form inclosing chambers for-the cam, cam shaft, andbearings. The front cover or resonator section 6 of thediaphragm case isshown as being substantially parallel with the diaphragm and far enoughaway from it to permit maximum vibration of the diaphragm withoutengagement with the case and has a central opening 7 of large diameterso as to expose a large portion of the effectively vibrating part of thediaphragm. The opening is surrounded by an annular flange 8. Theresonator 10 is secured to this flange preferably by spinning thematerial against the outer wall thereof or by brazing or by both. Theperiphery of the front section 6 is formed with a flange 11 fitted overthe rear section 2 of the diaphragm case. As shown in the drawings theclamping surfaces are of ample Width and thickness to apply the clampingpressure of the screws 12 evenly about the periphery of the diaphragm.The qualitv of the note is improved and destructive vibration andcutaction of the diaphragm is prevented by washers 13 and 14 arrangedbetween the diaphragm and the clamping faces of each section of thecase. These washers may be of non-vibratory material, such as cork,Wood, or hardened fiber.

The diaphragm 1 is shown as be1ng pro vided with a wear-piece 15 formedwith a shank 16 riveted over a washer 17. Th1 s wear-piece operates toreceive the thrusts from the thrust member as movement 1s rmparted tothe latter by the cam.

The section 2 of the diaphragm case is shown as being formed with webs18, 19, having alined cam shaft 20. The latter is mounted in a bearingsleeve 21 with its axis eccentric to but preferably parallel with theaxis of said hearing 21, as shown more clearly in Fig. 2. When saidbearing is rotated, the axis of the shaft moves in a circular pathapproximately parallel with the axis of the sleeve. In practice I findthat the radius of this eccentricity need not be much greater than the.amplitude of vibration of the diaphragm, in order to give a throw amplysufficient for all required adjustments of the power shaft withoutrespect to the diaphragm.

The sleeve bearing 21 is held in a desired position of longitudinaladjustment by means of the screw collar 22 engaging the end wall of thecasing. This collar is locked in position by means of a screw key 23,

v screw threaded into collar 22 and having a stud engaging a recess insleeve 21. There is a cooperating lock nut 25 outside of the casingwhich may be loosened to permit rotary adjustment of the sleeve bearing21 and the cam shaft 20 carried thereby and which may be tightened torigidly clamp saidbearing against both longitudinal and rotary movement.

The power shaft 20 is operatively arranged to vibrate the diaphragmpreferably through the medium of a rotary member 26, having eccentricsurfaces adapted to apply the power of the shaft to displace the thrustmember which in turn displaces the diaphragm to cause the desiredvibratory movements thereof. The eccentric surfaces on the rotarymember, as shown, are peripherally arranged cam surfaces, though it isobvious that I may use other equivalent eccentric surfaces. The rotarymember or cam 26 is rigidly secured to the cam shaft 20 in any desiredway and is prevented from endwise displacement therefrom by lock nuts29. The motor on the power shaft 20 'is free to vary its speed inproportion to the work done and is capable ofdriving the cam at suchspeed as to give the diaphragm its harmonious natural frequency ofvibration.

Oil for lubricating the shaft 20 and also the contact between cam 26,wear-piece 15 openings for support of the upon by the cam. The motor. isfree to va its elasticity and inertia. The thrust memin the form of aand the thrust member is supplied through an oil passage or reservoir30. -Part of the oil is thrown by centrifugal force from the rapidlyrevolving cam against the thrust member.

My invention as applied to the above construction, includes a' thrustmember 31' separate from the diaphragm and lateral guides 70, 70, onboth sides of the thrust member to position the latter. The thrustmemberis preferably separate and independent of the guides and is alsounattached to the diaphragm and capable of bodily movement an oilpassage or-reservoir 30. Part of the toward and from the diaphragm.Preferably it presents a curved contour or peripheral surface, and isfree to rotate about its own axis. -The thrust member is of suchdiameter and the cam is of such shape and so located in respect theretoand to the diaphragm, that the diaphragm is positively forced by thethrust member a slight distance beyond its normal plane and while saidthrust member is being directly acted its speed in proportion to the andupon high speed rotation the diaphragm is forced by harmoniouspositively and rigidly applied thrusts of the cam through the thrustmember to a predetermined distance beyond normal and is permitted toswing freely a desired distance beyond the forcing movement according toits own natural movement as determined by work -done,

her is preferably of hardened steel and either cylinder or in the formof a ball, the one having the advantage of line contact and distributedapplication of power and wear, whereas the other has point contact andless mass and less momentum.-

The guides are formed as part of a bridge piece 71 secured to the faceof the. casing by screws 72, 72, and provision for adjustment of theposition of the guide is made 1 by having the holes 74 somewhat largerthan the shanks of the screws 72. The vertical surfaces of the guides 7Oand the amount of projection of the anvil or wear-piece from thediaphragm, are so proportioned that the 1 latter may vibrate freelywithout danger of striking the guides. The guides and adjacent portionsof the supporting bridge piece are preferably cutaway, as at 76, 75, to.permit necessary adjustment of the cam, 1 without danger of contact withthe guide or guide supports.

In order to prevent the thrust member from possibility of the strikingor becoming jammed in the guide, the faces of the thrust memberpresented in the direction of reta tion of the cam, in case said memberis not rotatable, are curved and the ends of the thrustmemberare'preferably out along the surfaces of of tlie cam a cylinderhaving. an axis pass- T ing throu h the axis of thadiaphragm. Thus the%hrust. member has line or point contact with the guide instead ofsurface contact, the essential being that the sides and ends of thethrust member fit the gu de through the limited range of angulardisplacement which is likely to occur during vibrations of thediaphragm.

In Figs. 1 and 2 I have shown the cylindrical rotatable thrust memberwith its ends curved. It is not essential that the ends of the thrustmember be curved as the edges may be merely rounded as indicated in Fi3. In this Fig. 3 I have shown a cylin or 110 with rounded edges mountedin a uide 10& the opposite walls of which are s ightly convex. Thiscylindrical body may be bored as at 111 and may be made as a tube ofspring steel;

In Fi s. i and 5, the diaphragm is shown as provided with a wear-piece100 and a spherical thrust member 101 is interposed betweenit and thecam. The guides 102 hold the sphere in position against displacementexcept in the direction of vibration of the diaphragm. A convenientarrangement for this guide is illustrated in Fig. 4 where thecylindrical ends of the guides 102 are rigidly connected by side bars103 secured thereto by screws 104;. The guides need not have the uidingflanges 70 as indicated in.

Figs. 1 an 2 as a small aperture in the guide is sufficient if the rangeof movement of the thrust member be comparatively small. In Fig. 6,'Ihave shown a thrust member in the form of a cylinder 76 having roundedends 77 and merely placed in an aperture in a bar 78 constituting thebridge piece or guide. Here the walls of the guide passage are straightinstead of being convex as'in Fig. 3 or concave as in Fig. 4.

It will be noted that the thrust member is free to rotate about its ownaxis, thus as the cam in moving across one side of the thrust membertends to rotate the thrust member the wear will be distributed and foreach thrust by the cam a new surface will be presented. Furthermore, theturning of the thrust member reduces the wear both at the point ofengagement of the cam with the wear-piece and at the point or line ofengagement between the thrust member and the wear-piece. The thrustmember acts to positively transmit the force of the cam to the diaphragmand to give the latter a partly forced and partly free movement, insteadof being projected from the cam toward the diaphragm to cause the latterto vibrate by the force of the blow delivered fromthe thrust member.This latter operation is not ordinarily desirable as in suchconstruction the force of the blow is dependent solely upon the mass andspeed of the thrust member rather than upon the power applied to the camand there is less automatic governing of the speed of the motor.

Having thus described my invention, what I claim as new and desire toprotect by Letters-Patent is i .1. In an alarm or signaling device ofthe class described, a horn or resonator and a diaphragm in combinationwith a rotor having a plurality of cam projections spaced apart andmeans for rotating it at high eed e pe Qt r ta i an o fi retion of thecam projections being such as to mechanicallyand positively forceoutward movement of the diaphragm at such velocity as to cause furtheroutward movement of the diaphragm in the same direction by momentumagainst increasing elastic stress and to, permit free inward movement ofthe diaphragm to, a predetermined distance on the other side of normal,a thrust member intermediate of said rotor and said diaphragm andunattached to. the latter and driven by the cams, and a guide for saidthrust mem- 2. In an alarm or signaling apparatus of the classdescribed, a horn or resonator and a diaphragm in combination with arotary cam, a thrust member actuated by said cam and a support forconfining the bodily motion of said thrust member to a directionperpendicular to the diaphragm, said thrust member being rotatable aboutan axis parallel to said diaphragm and having opposed curved bearingsurfaces in engagement with the surfaces of the support.

3. In a device of the class described, a motor free to vary its speed inproportion to the work done, a rotary cam mounted on the motor shaft, anelastic diaphragm having a natural frequency of vibration, a ballintertoo slight distance beyond its normal plane, 7

whereby upon high speed rotation of said cam said diaphragm is forced byharmonious positively and rigidly applied thrusts of the cam through theball to a predetermined distance beyond normal and is permitted to swingfreely a desired distance beyond the forcing movement, according to itsown natural movement as determined by its elasticity and inertia andsaid ball being free to rotate about an axis parallel to said diaphragmas said cam engages with and passes the same. 4. In an alarm signal ofthe character described, a diaphragm, a plurality of cams, a rotatablecarrier for said'cams, an intermediate thrust transmitter arrangedbetween said cams and said diaphragm, and simultaneously contacting withsaid diaphragm and I member said diaphragm While being one of said camsto forcibly displace said diaphragm, and a support for said intermediate thrust transmitter independent of said diaphragm, said thrusttransmitter being in the form of a steel ball free to rotate.

5. In an alarm signal of the character described, a diaphragm, arotatable member presenting a series of cam surfaces, an intermediatethrust transmitter arranged between said cam surfaces and saiddiaphragm, and simultaneously contacting with said diaphragm and one ofsaid cams to forcibly displace said diaphragm, and a support for saidintermediate thrust transmitter independent of the diaphragm, saidthrust transmitter being free to rotate about its ownaxis.

6. In an alarm or signaling apparatus of the class described, a horn orresonator and a diaphragm, in combination with a rotary member havingspaced cam projections, a thrust member unattached to said diaphragm andadapted to forcibly displace said diaphragm While being forced by saidcam projections and to enter between said projections upon the reversevibration of said diaphragm, and a guide having a passage for confiningthe motion of said thrust to a direction perpendicular to the diaphragm,said thrust member being formed with lateral bearing surfaces curvedabout an axis parallel to said diaphragm for engagement With the Wallsof said guide passage. j

7. In an alarm or signaling apparatus of the class described, a horn orresonator and a diaphragm, in combination with a rotary member havingspaced cam projections, a thrust member adapted to forcibly displaceforced by said cam projections and to enter between said projectionsupon the reverse vibration of said diaphragm, and a guide having apassage for confining the motion of said thrust member to a directionperpendicular to the diaphragm, said thrust member being rotatable aboutan axis parallel to said diaphragm to permit the lateral movement of thesurface of said thrust member farthest from said diaphragm as the camprojections engage with and pass said surface.

In an alarm or signaling device" of the class described, a diaphragm, arotor, and means for driving the latter in combination with a rollingcontact thrust member, and means for rotatably holding said member in anormal position in the line of thrust between said rotor and diaphragm.

9. An alarm or signal having a rotor having a contour adapting it toexert thrust, a diaphragm, a rolling contact member interposed as athrust member between the rotor and diaphragm and having a normalposition therebetween, and means for preventing displacement of themember without preventing rotation thereof.

10. An alarm or signal having a diaphragm and cam in combination With arolling contact member having a normal position therebetween and actingas a thrust member, and means for rotatably holding it at the center ofthe diaphragm and in operative relation to said cam.

11. A mechanical horn embodying therein a flexible diaphragm, aWear-piece rigidly secured thereto at the center thereof, a diaphragmcasing member having its peripheral portion held rigid in respect to theperipheral portion of the diaphragm, a guide member rigidly securedthereto and having a portion disposed adjacent to but spaced from saidearpiece, said portion having an aperture substantially in axialalinement With said Wear-piece, a drive shaft projecting through saidcasing member, a rotor carried by said drive shaft and presenting aseries of spaced ;projections, and

a thrust member disposedwithin said aperture and rotatable about its owncenter and serving to engage with said Wear-piece and repeatedlyforcibly displace said diaphragm upon the rotation of said rotor.

12. A mechanical horn'embodying therein a flexible diaphragm, a framemember held rigid in respect to the peripheral portion of the diaphragmand having a portion adjacent to but spaced from the center of saiddiaphragm and having an aperture in axial alinement with said diaphragm,a thrust member rotatable about an axis parallel to said diaphragmwithin said aperture and guided in a direction substantially at rightangles to said diaphragm, and a rotor having a series of projectionsadapted to successively engage with said thrust member and forciblydisplace said diaphragm.

Signed at West Orange Essex and State of New Jersey this twentyseventhday of February A. D. 1912.

C. W. FAIRBANK, FLORENCE LEVIEN.

Copies-0f this patent may be obtained-for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

in the county of-

